High molecular weight alkenyl succinic derivatives are effective dispersants in lubricating oils. For example, alkenyl succinimides of various amines are described in U.S. Pat. Nos. 3,219,666 and 3,172,892. Alkenyl succinic esters are described in U.S. patent application Ser. Nos. 3,381,022 and 3,331,776. Dispersants containing both ester and amide groups are disclosed in U.S. Pat Nos. 3,184,474 and 3,804,763.
Many of these dispersants provide adequate dispersancy but tend to produce piston lacquer when used in internal combustion engines.